1. Field of the Invention
The present invention relates generally to a digital living network alliance (DLNA) system, and in particular, to a method for sharing contents between devices using an Institute of Electrical and Electronics Engineers (IEEE) 1394 interface in a DLNA system.
2. Description of the Related Art
Home network technology provides a future-oriented home environment in which all information home appliance devices are connected by a wire/wireless network, and provide anyone with a variety of high quality home services without restriction as to device type, time, and place. The home network is regarded as a starting point and the most important component of a ubiquitous environment and associated technology is being continuously researched.
A standard organization for the home network technology is the Digital Living Network Alliance (DLNA). The DLNA is a succeeding standard organization of the existing Digital Home Working Group (DHWG). In June 2003, the DLNA was established by MS, IBM, HP, Intel, SONY of Japan, Samsung Electronics of Korea, etc., to address compatibility problems that are obstacles to common use of a home network. The DLNA consists of five committees: Technical Committee, Ecosystem Committee, Legal Committee, Interoperability & Compliance Committee, and Marketing PR Committee, and in addition, consists of six sub committees.
The DLNA defines a network coexisting in a home as a personal computer (PC) Internet network (PC, printer, facsimile, etc.), a mobile network (PDA, mobile phone, notebook computer, etc.), and a home appliance network (television, audio, DVD player, etc.). The DLNA attempts to provide interoperability of these networks using three methods of cooperation between main industries, a standardization of a mutual operability framework, and a product observing them.
Specifically, a technology considered by the DLNA is to allow a consumer to obtain many digital multimedia contents (photograph, music, video, etc.) from personal devices like a mobile device or a personal computer, and transport and manage the obtained contents. In other words, the technology allows a consumer to conveniently enjoy the digital multimedia contents irrespective of the consumer's location and a device's location within a home.
For this, the DLNA is proceeding with standardization of a physical media, a network transmission, a media format, a streaming protocol, a digital rights management (DRM), etc. on the basis of a Universal Plug and Play (UPnP).
The DLNA is now described in more detail. In the DLNA, networking is based on Internet protocol (IP). The IP is a basic network communication protocol of a device operating on the Internet that allows information of an application program operating in various media to be exchanged in a transparent manner.
For example, the PC or a set-top box (STB) can transport the digital multimedia contents to a home television by wireless, using an IEEE 802.11 access point (AP) connected to an Ethernet cable. As such, all DLNA devices can communicate with other devices connected to the Internet, using the IP, anywhere in the whole world.
A physical layer of the DLNA employs a wire high speed Ethernet (IEEE 802.11u) and a wireless Ethernet (IEEE 802.11a/b/g). The wire Ethernet has already demonstrated stability, and the wireless Ethernet has adopted a wireless-fidelity (Wi-Fi) as wireless home network communication increases.
A technique for detecting and controlling a device within a DLNA network is to automatically configure networking settings such as an IP address, and recognize and manage other devices on the network, and is based on existing UPnP AV architecture and UPnP device architecture. A technique for detecting and controlling a service within the DLNA network is also available.
In the DLNA, a device class is based on a digital media server (DMS) and a digital media player (DMP). The DMS performs a function of a media server device (MSD). That is, it performs a function of a server providing a media in a UPnP specification. The DMP performs functions of a media renderer device (MRD) and a media renderer control point (MRCP). That is, it performs functions of selecting and controlling a media, and playing the selected media.
FIG. 1 illustrates a construction of a conventional DLNA system.
As shown in FIG. 1, the DLNA system includes a digital media server (DMS) 110 for providing media contents 100, such as broadcasting A/V (audio/video) 101, comprising an application 102, and an SI (service information) information 103; and a digital media player (DMP) 130 for executing the media contents 100. In general, the DMP 103 comprises an integration of a plurality of wire/wireless DMPs. The DLNA system includes a network connection function (NCF) 120 as a middle node for connecting the DMP 130 with the DMS 110.
An existing communication protocol for connecting the DMP 130 with the NCF 120 includes Bluetooth and a wireless local area network (WLAN). The communication protocol may include and use ZigBee and a personal area network (PAN) that are typical technologies of a wireless sensor network characterized by lower power, lower cost, and ease of use in comparison to Bluetooth according to the planned future development of wireless network technology. In ZigBee, upper protocol layers and application are regularized on the basis of a PHY/MAC layer standardized in a 2003 IEEE 802.15.4 working group committee. The PAN is a personal local communication network defined on the basis of a human life style.
In the DLNA system, generally, the DMS 110 informs DLNA-compatible devices that the DMS 110 itself is a DMS. The DMP 130 having a rendering function accesses the DMS 110 and browses a contents (item) list of the DMS 110. The DMP 130 renders the contents using the contents (item) list received from the DMS 110.
In rendering the contents, a connection between the DMP 130 and the DMS 110 is generated, and the contents are transported to and rendered in the DMP 130 using hyper text transfer protocol (HTTP)-GET and real-time streaming protocol (RTSP) methods and the like. A method for transporting the contents from the DMS 110 to the DMP 130 is now described with reference to FIG. 2.
FIG. 2 is a ladder diagram illustrating a conventional method for receiving the contents in the DLNA system.
Using “SetAVTransport URI action” (Step 201) the DMP 130 transports to the DMS 110 a uniform resource identifier (URI) of the contents to be rendered, such as
http://hostname/video-content/test.mpg,
rtsp://hostname/video-content/birthdayparty.m2v.
Using the received URI (Step 202), the DMS 110 generates an AV transfer connection between the DMP 130 and the DMS 110.
When the AV transfer connection is generated between the DMP 130 and the DMS 110, the DMP 130 transmits a “HTTP-GET” message requesting the transport to the DMS 110 (Step 203) of the A/V content of the URI.
The DMS 110 then provides the A/V contents to the DMP 130 (Step 204).
Using the above method, the DMP 130 can receive the contents from the DMS 110.
However, currently there is provided only HTTP-GET and RTP/RTSP that are protocols for contents transport defined in a UPnP AV stack. A protocol for contents transported in an IEEE 1.394 interface, that an AV home appliance device uses a majority of the time, currently has not been defined.
Accordingly, the DLNA has a goal of sharing contents without restricting such sharing to a device, a vendor, an operating system, etc., but has a drawback that it is impossible to share the contents since the DLNA protocol for the contents transport is not defined for the device using the IEEE 1394 interface.